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United States Patent |
5,119,724
|
Ng
|
June 9, 1992
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Force adjustment device in a manual pad printer
Abstract
A pad printer device includes a base member (2), a table member mounted on
the base member, a slide member (3) slidably mounted on the table member
for movement between at least two positions, and a printing pad (17)
supported on printing arm (16) mounted on a support block (15) slidably
mounted in a box-like column (9) extending upwardly from base (1).
Printing pad (17) is reciprocated vertically by lever-type arm (25)
pivotally engaged (27, 28) with support block (15) so that operation of
the arm reciprocates the printing pad vertically. An adjustable limit
gauge device is mounted on slide block (15) and includes two separately
operable set screws (30, 31) which separately engage with rotatable stop
member (47) rotatably mounted on base member (1) for positioning thereof
for engagement with the lower ends of the set screws. The stop member (47)
is rotated by a cam (46) connected thereto through a cam sleeve (45)
pivotally mounted on a cam shaft (43 ), the cam (46) having parts (48, 49)
extending into the path of movement of a cam operator (40) mounted on
sliding block (36) which is part of the slide assembly, so that
reciprocation of slide assembly (3) in one direction rotates stop member
(47) into position for engagement with the lower end of one of the gauge
screws and operation of block (36) in the opposite direction rotates stop
member (47) in the opposite direction for engagement with the lower end of
the other gauge screw, so that the force applied by printing pad (17) is
controlled, or standardized, for each operation thereof in either position
of the slide assembly (3).
Inventors:
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Ng; Hin-Chung (Tuen Mun, HK)
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Assignee:
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Tai Chung Metal Factory (Tuen Mun, HK)
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Appl. No.:
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684282 |
Filed:
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April 12, 1991 |
Foreign Application Priority Data
Current U.S. Class: |
101/41; 101/104; 101/287 |
Intern'l Class: |
B41F 017/00 |
Field of Search: |
101/103,109,35,41,327,333,334,318,193,287,292,42,104
|
References Cited
U.S. Patent Documents
1657237 | Jan., 1928 | Talbot | 101/41.
|
2777385 | Jan., 1957 | Bachy | 101/42.
|
3094926 | Jun., 1963 | Mintz | 101/318.
|
4163421 | Aug., 1979 | Sihota | 101/41.
|
4314504 | Feb., 1982 | Combeau | 101/41.
|
Foreign Patent Documents |
500080 | Apr., 1976 | SU | 101/41.
|
269494 | Jul., 1927 | GB | 101/41.
|
Primary Examiner: Burr; Edgar S.
Assistant Examiner: Yan; Ren
Attorney, Agent or Firm: Fleit, Jacobson, Cohn, Price, Holman & Stern
Claims
I claim:
1. A pad printer device comprising:
a base member having a front side, a rear side and top surface;
a table member mounted on said top surface of said base member and having a
front side, a rear side and opposite ends;
a slide assembly slidably mounted on said table member for movement
relative to said base member;
an upstanding column having a lower end mounted on said base member
adjacent the rear side thereof, an upper end, an open front side, a rear
side and two spaced opposing sides extending from said rear side of said
column, so that said column is substantially box shaped having a hollow
interior;
a plurality of guide rods extending upwardly through the interior of said
column, each guide rod having a lower end mounted in said lower end of
said column and an upper end mounted in said upper end of said column;
a printing pad support block slidably mounted on said guide rods for
reciprocal substantially vertical movement on said column;
a printing pad support arm connected to and extending from said printing
pad support block over said slide assembly;
an outer end on said printing pad support arm displaced from said printing
pad support block;
a printing pad mounted on said outer end of said support arm and having a
pad portion facing downwardly towards said slide assembly;
printing pad operating means connected to said printing pad support block
for moving said printing pad support block reciprocally on said column;
image plate means mounted said slide assembly;
printing table means mounted on said slide assembly adjacent said image
plate means;
means for moving said slide assembly reciprocally to selectively position
one of said image plate means and printing table means directly under said
printing pad for engagement thereby;
gauge plate means mounted on said printing pad support block for
reciprocating movement therewith;
two gauge screws threadedly engaged and separately operable in said gauge
plate means for adjustment relative to said base member;
stop means rotatably mounted on said base member into respective positions
for engagement with said respective gauge screws for limiting downward
movement of said printing pad, respectively;
cam operating means connected to said slide assembly for movement
therewith; and
cam means rotatably mounted on said base member for engagement by said cam
operating means and interconnected with said stop means, so that when said
slide assembly is moved into the position wherein said image plate means
is beneath said printing pad said cam operating means engages said cam
means and rotates said cam means and said stop means into position for
engagement of said stop means by one of said gauge screws, and when said
slide assembly is moved in the opposite direction to position said
printing table means beneath said printing pad, said cam operating means
engages said cam means and rotates said cam means in the opposite
direction to rotate said stop means into position for engagement by the
other of said gauge screws.
2. A pad printer device as claimed in claim 1 wherein said cam means
comprises:
a cam shaft having one end mounted in said lower end of said column and
extending upwardly therefrom;
a cam sleeve coaxially and rotatably mounted on said cam shaft and having
upper and lower ends said stop means being connected to said upper end of
said cam sleeve; and
a cam plate on said lower end of said cam sleeve engageable by said cam
operating means for rotating said cam sleeve and stop means thereon in
response to said movement of said slide assembly.
3. A pad printer device as claimed in claim 2 wherein said cam plate
comprises:
a central part;
two spaced cam fingers extending from said central part; and
a groove between said fingers for receiving said cam operating means, so
that said fingers independently engage said cam operating means.
4. A pad printer device as claimed in claim 1 wherein said stop means
comprises:
a disc member having a central part and a stop part extending therefrom for
separate and independent engagement by one of said gauge screws.
5. A pad printer device as claimed in claim 2 wherein said stop means
comprises:
a disc member having a central part and a stop part extending therefrom for
separate and independent engagement by one of said gauge screws.
6. A pad printer device as claimed in claim 3 wherein said stop means
comprises:
a disc member having a central part and a stop part extending therefrom for
separate and independent engagement by one of said gauge screws.
7. A pad printer device as claimed in claim 1 wherein:
said slide assembly comprises a plurality of substantially horizontal guide
rods mounted on said table member, a slide block slidingly and guidingly
mounted on said horizontal guide rods and having a rear side, and a slide
plate mounted on said slide block; and
said cam operating means comprises a plate member connected to said slide
block and having a cam means engaging part extending outwardly of said
rear side of said slide block.
8. A pad printer device as claimed in claim 2 wherein:
said slide assembly comprises a plurality of substantially horizontal guide
rods mounted on said table member, a slide block slidingly and guidingly
mounted on said horizontal guide rods and having a rear side, and a slide
plate mounted on said slide block; and
said cam operating means comprises a plate member connected to said slide
block and having cam means engaging part extending beyond said rear side
of said slide block.
9. A pad printer device as claimed in claim 3 wherein:
said slide assembly comprises a plurality of substantially horizontal guide
rods mounted on said table member, a slide block slidingly and guidingly
mounted on said horizontal guide rods and having a rear side, and a slide
plate mounted on said slide block; and
said cam operating means comprises a plate member connected to said slide
block and having a cam means engaging part extending outwardly of said
rear side of said slide block.
10. A pad printer device as claimed in claim 4 wherein:
said slide assembly comprises a plurality of substantially horizontal guide
rods mounted on said table member, a slide block slidingly and guidingly
mounted on said horizontal guide rods and having a rear side, and a slide
plate mounted on said slide block; and
said cam operating means comprises a plate member connected to said slide
block and having a cam means engaging part extending outwardly of said
rear side of said slide block.
11. A pad printer device as claimed in claim 5 wherein:
said slide assembly comprises a plurality of substantially horizontal guide
rods mounted on said table member, a slide block slidingly and guidingly
mounted on said horizontal guide rods and having a rear side, and a slide
plate mounted on said slide block; and
said cam operating means comprises a plate member connected to said slide
block and having a cam means engaging part extending outwardly of said
rear side of said slide block.
12. A pad printer device as claimed in claim 6 wherein:
said slide assembly comprises a plurality of substantially horizontal guide
rods mounted on said table member, a slide block slidingly and guidingly
mounted on said horizontal guide rods and having a rear side, and a slide
plate mounted on said slide block; and
said cam operating means comprises a plate member connected to said slide
block and having a cam means engaging part extending outwardly of said
rear side of said slide block.
Description
BACKGROUND OF THE INVENTION
This invention relates to a manual pad printer, and more particularly to a
force adjustment device for such a manual pad printer to control the
amount of force applied to the image plate or printing object through the
pad.
Manual pad printing devices have been known wherein a manually operated pad
generally movable upwardly and downwardly is first moved downwardly to
apply the printing pad to the image plate to absorb the printing ink from
the image plate printing pad, whereafter the printing pad is raised and
subsequently lowered onto the printing table which has been positioned
beneath the pad to print the ink thereon onto an object on the printing
table, after which the pad is raised again for repeating the same sequence
of operations for printing another object. However, in prior art devices
it is difficult to control the force applied to the image plate, or to the
printing object, through the pad, so that this force is applied uniformly.
Thus, the printing effect cannot be standardized.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide a manually operated pad
printer which overcomes the above problem by controlling the force applied
to the image plate, or the printing object.
It is a further object of this invention to provide an improved manually
operated pad printer having an adjustable gauge device integral therewith
to control the force applied to the image plate, or the printing object
through the pad.
It is another object of the invention to provide a manual pad printer
having a force control device thereon for effecting uniform force on to
the image plate and printing object so that the printing effect is
standardized.
The above objects are achieved in the instant invention wherein a base
member having a slide assembly slidably mounted thereon has an upstanding
column supported on the rear side of the base member adjacent the slide
assembly, and a printing pad slidably mounted on the column for
reciprocating vertical movement for selective engagement with an image
plate and a printing table mounted on the slide assembly when the latter
is shifted from the position for engagement of the printing pad with the
image plate and for engagement with the object to be printed on the
printing table. A gauge plate is mounted on the device to move with the
printing pad support arm and has threadedly engaged therewith a pair of
elongated set screws, or gauge screws extending substantially vertically.
A stop member is rotatably mounted on the base member for oscillating
rotational movement into positions for alternately engaging the lower end
of one of the gauge screws to limit the downward movement of the printing
pad and thereby control the force applied thereby. The stop member is
rotated by a cam assembly interengaged therewith and operated to shift the
stop member into the appropriate position in response to reciprocating
movement of the slide assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in detail with reference to the
accompanying drawings, wherein:
FIG. 1 is a perspective view of the manual pad printer of this invention
showing the printing pad in a raised position;
FIG. 2 is a rear perspective view of the device of FIG. 1;
FIG. 3 is a view similar to FIG. 1 showing the printing pad lowered to
engage the mold plate;
FIG. 4 is a view similar to FIG. 1 showing the printing pad lowered to
engage the object to be printed after the slide has been moved to the
right; and
FIG. 5 is an enlarged perspective view of part of the device of FIG. 1 with
parts omitted to show details of the force control device of the invention
.
DETAILED DESCRIPTION
With reference to the drawings, FIG. 1 shows a perspective view of the
invention wherein a base member 1 has mounted thereon a table member 2 on
which is slidably mounted a slide assembly 3 (hereafter "slide") for
sliding movement in the longitudinal direction of the table shown
generally by arrow 4. The details of the slidable mounting of slide
assembly 3 on table 2 will be described hereinbelow. On one part of slide
3 is image plate assembly 5 which contains the printing ink in the area
indicated at 6. On the other part of slide 3 is printing table 7 on which
the object 8 to be printed is supported.
On the rear part of base 1 is mounted, by suitable means such as welding or
screw fasteners, an upstanding column 9 of generally channel shape having
two sides 10, 11, rear sid top end 13. Guide rods 14 extend upwardly in
the vertical direction of column 9 and are connected at their upper ends
to end 13 and at their lower ends in base member 1. Printing pad mounting
block 15 is slidingly mounted within column 9 on guide rods 14 for
vertical movement, and has printing pad arm 16 mounted thereon, such as by
welding or suitable fastening means, and extending outwardly therefrom
into the area over slide 3 and the image plate assembly and printing table
thereon. Printing pad 17 is mounted on the outer end of arm 16 for
vertical adjustment by means of a screw threaded shaft 18 extending from
the upper part thereof through an internally threaded bore in block 19
mounted in arm 16 by screws or bolts. Rear side 12 of column 9 has guide
slot 20 therein for a purpose which will later be explained.
Extending outwardly from column 9 to the left as shown in FIG. 1 is support
arm 21 to which is pivotally connected at 22 link 23 which is also
connected pivotally at 24 to one end of operating arm 25. The other end of
operating arm 25 has handle 26 thereon. Between its ends arm 25 is
pivotally connected to mounting block 15, as more clearly shown in FIG. 2,
by a shaft or pin member 27 mounted in block 15 and extending through
guide slot 20 to pivotally engage with arm 25 by a suitable bearing means
28. Thus, members 21, 22, 23, 24, 25, 26, 27, and 28 form a toggle arm
assembly for reciprocally operating sliding block 15 and printing pad 17
thereon vertically.
A gauge plate 29 is mounted on mounting block 15, by suitable means such as
welding or screw fasteners (not shown) and has threadedly engaged therein
in spaced relation gauge screws 30 and 31 having heads at their upper ends
for turning the gauge screws for adjusting their relative positions in
threaded bores in gauge plate 29 for a purpose which will appear below.
Gauge plate 29 could alternatively be mounted on arm 16.
The details of slide assembly 3 and the force control features will now be
described. Within table 2, which is hollow, are mounted two parallel guide
shafts 34, shown in FIG. 4 which shows the slide assembly shifted to the
right, or printing position. Guide shafts 34 are mounted at each end
thereof in opposite ends 35 of table 2. Slide mounting block 36 as shown
in FIG. 5 is slidably mounted on guide shafts 34 for sliding movement
thereon. Slide 3 is supported on mounting block 36 by suitable fasteners,
for example, such as screws or bolts (not shown) engageable in threaded
bores 37 in block 36. Handle 38 is provided on slide 3 for manually
transferring or shifting slide 3 between the operating positions of the
machine, as will be understood in the further description herein. Set
screws 39 are provided in ends 35 to function as stops to limit the
movement of mounting block 36. A cam operator 40 is mounted on block 36 as
shown in FIG. 5 by screw type fasteners 41, for example, and is provided
with a bore 42 through which one of the guide shafts 34 passes without
interference. Cam operator 40 in the embodiment illustrated is in the form
of a plate which extends beyond the rear side of block 36 in the direction
of column 9. A vertical cam shaft 43 is mounted at its lower end in the
bottom 44 of column 9 and could extend into base member 1. A cam sleeve 45
is rotatably mounted coaxially on shaft 43 and has mounted non-rotatably
on the lower end thereof cam 46 and non-rotatably mounted on the upper end
thereof stop plate 47 so that elements 46 and 47 rotate together with
sleeve 45. Cam 46 has two cam operator extensions or fingers 48, 49
thereon between which is a cutout or groove portion. Finger extensions 48
and 49 extend into the path of movement of the rear edge of cam operator
40 so that when slide block 36 is shifted along guide rods 34 the rear
edge of cam operator 40 will engage cam fingers 48 and 49 and within the
groove therebetween to operate cam 46 to rotate sleeve 45 and thereby stop
plate 47 about the axis of shaft 43. More specifically, cam finger 48 may
be longer than cam finger 49, with respect to the rotational axis of shaft
43 and sleeve 45. When cam operator plate 40 moves to the left, as shown
in FIG. 5, it engages cam finger 49 and rotates sleeve 45 and stop plate
47 clockwise, and when cam operator plate 40 is shifted to the right, it
engages cam finger 48 and rotates sleeve 45 and stop plate 47
counterclockwise, thereby positioning stop plate 47 to engage alternately
the lower end of either gauge screw 30, or 31. Stop plate 47 has a planar
disc shape with extension or finger 50 extending outwardly therefrom so
that it is engageable with the lower ends of gauge screws 30 and 31.
The operation of the pad printer of this invention will now be described.
FIG. 1 shows the device with the handle 26 in the raised position to raise
printing pad 17 to the neutral position above table 2 and slide 3. Slide 3
is shown approximately in a neutral position. In this position, or in a
position where slide 3 is moved slightly to the left, as shown in FIG. 3,
slide mounting block 36 and cam operator 40 thereon have moved to the left
to engage cam leg 49 and rotate stop plate 47 clockwise into position for
engagement with the lower end of gauge screw 31 for limiting further
downward movement of arm 16. When slide 3 is adjusted to position image
plate assembly 5 and the printing ink area 6 thereon directly under
printing pad 17, arm 25 is pushed downwardly to lower printing pad 17 onto
area 6, as shown in FIG. 3, where printing pad 17 picks up the the
printing ink form the surface 6, after which arm 25 is again raised to
raise printing pad 17 off of surface 6 so that slide 3 can be transferred
to the printing position. FIG. 4 shows the printing position wherein slide
3 has been moved to the right to position printing table 7 directly below
printing pad 17. With the sliding of slide 3 to the right with block 36,
cam operator 40 engages finger 48 of cam 46 and rotates sleeve 45 and stop
plate 47 counterclockwise so that extension 50 on stop plate 47 is
directly beneath gauge screw 30 so that it will engage the lower end of
said screw 30 to limit movement of arm 16 when the printing pad is lowered
into the printing position. With transfer slide 3 in this position, arm 25
is operated to lower printing pad 17 onto object 8 positioned on the top
of printing table 7 for performing a printing operation thereon. The set
screws 30, and 31 are previously adjusted into predetermined positions to
limit the downward movement of slide block 15 and arm 16 and thereby the
amount of force applied by the printing pad 17 on the surface 6 and on the
object 8 to be printed, respectively, by engagement of the lower ends of
the gauge screws with stop plate 47. Thus, with the gauge screws 30 and 31
preset in the desired positions, the amount of force applied by pad 17
will always be the same during repeated use of the device to perform the
printing operations. In other words, with the invention the force applied
by the printing pad 17 is positively controlled so that the printing
operation is standardized for continuous use on a plurality of objects 8.
Coil spring 52 is provided around guide rod 14 and engages at its upper end
arm 16, or block 15, and at its lower end adjustable stop collar 54 which
has set screw 56 thereon for engaging shaft 14 to fix collar 54 in a
position to compress spring 52 a desired amount to return, or assist in
returning, arm 16 and printing pad 17 to the raised position.
Generall at 58 is a wiper assembly for treating the surface 6 of image
plate 5.
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